1. Field of the Invention
This invention is generally related to a hybrid type magnetic head slider having a thin film coil and a manufacturing method thereof, in particular, related to those applied to a magnetic recording apparatus such as a hard disk apparatus and a floppy disk apparatus which are auxiliary recording apparatus for an electric computer.
2. Description of the Prior Art
Magnetic recording apparatus could be classified into two types one of which uses a flexible medium as a floppy disk apparatus and the other of which uses a hard medium as a hard disk apparatus.
At present, a plastic film is mainly applied as the flexible medium to an apparatus having a storage capacity of about 120 mega-bytes or less, and a glass or aluminum plate or the like is largely applied as the hard medium to an apparatus having a storage capacity of more than 120 megabytes. The flexible medium of the former is rotated at a rotational speed of from several hundreds to several thousands of revolutions per minute, and is subjected to writing and reading of information through contact with a magnetic head slider. On the other hand, the hard medium of the latter is rotated at a rotational speed of several thousands of revolutions per minute, and the magnetic head slider performs writing and reading of information while it keeps floating over the medium at a distance of several tens nm.
Summarizing the basic structures in common with both media, though both types are slightly different from each other, there is a ground film on a substrate in general. There are formed a single layer or multiple layers of magnetic powders of .gamma.-Fe.sub.2 O.sub.3, Co metamorphic .gamma.-Fe.sub.2 O.sub.3, CrO.sub.2, Fe alloys, barium ferrite or the like on the surface of the ground film, and there are further deposited thereon an amorphous carbon film, DLC (diamond-like carbon) film, SiO.sub.2 film or the like as a protective coat. The outer surface is finally coated with a lubrication film of fluoropolymers.
On the other hand, a magnetic head slider comprises a housing made of non-magnetic ceramic materials such as zirconia ZrO.sub.2, barium titanate BaTiO.sub.3, calcium titanate CaTiO.sub.3, alutic Al.sub.2 O.sub.3 -TiO.sub.3 or the like and a ferrite core part having a small gap to face a magnetic recording medium for writing and reading.
Since a magnetic head slider contacts a magnetic recording medium rotating at a high speed during a read/write operation, a contacting part of the flexible type medium is liable to abrasion. Such a phenomenon may occur also when a hard type medium is used, however, it is a more serious problem in a flexible type medium because a flexible type medium is subjected to elastic deformation due to a pressure from a magnetic head slider while it rotates at a high speed and therefore is liable to more abrasion than a hard type medium.
As the prior art disclosing a magnetic head slider applicable to a fixed type hard medium, for example, Japanese Patent Laid-Open No. 6-20245, Japanese Patent Laid-Open No. 6-76223, Japanese Patent Laid-Open No. 6-76224 and the like are known.
Referring to Japanese Patent Laid-Open No. 6-20245 taken from among those in detail, FIG. 20 is a partly enlarged perspective view showing a magnetic head slider disclosed in the prior art. As clearly seen from FIG. 20, the magnetic head slider comprises a substrate 100 of a non-magnetic body provided with a triangular cut groove 101 on one corner and two rails 103, 104 formed on both sides of an upper surface 102 of the substrate 100. There is formed an air flow path between the rails 103, 104. A magnetic core part 105 to perform reading and writing of data with a magnetic recording medium (not shown) is attached to a side surface of the substrate 100. Also a coil 106 for read/write operation is wound on the core part 105. As seen from the enlarged part of FIG. 20, a slant part 107 is provided at the front part of the magnetic core part 105, and a width 108 of a plane area flush with the rail 104 is minimized to be the same as a track width of a high density recording medium. In addition, a numeral 109 indicates a magnetic film attached to the inside of the magnetic core part for decreasing magnetic resistance, and a numeral 110 denotes a gap part formed in the magnetic core part.
As seen from FIGS. 20 and 21, the magnetic core part 105 is positioned at the side surface of the substrate 100 and in parallel to a traveling direction of a magnetic recording medium. Whether a recording medium is of a hard type or of a flexible type, as long as the medium is rotated normally and the magnetic head slider is not vibrated, a slidable surface of the magnetic core part 105 is able to keep a floating position at a certain distance from the medium not to contact therewith because a fluid dynamic interaction occurs between the magnetic head slider and the magnetic recording medium. Thus, a stable traveling can be obtained. Referring to a flexible magnetic recording medium, a magnetic head slider travels in contact with the traveling surface of the medium 111 which rotates at a high speed and is subjected to elastic deformation locally as shown in FIG. 22, and when the traveling surface is shifted for any reason, such deformation and abrasion of an outer edge 112 of the magnetic head slider are promoted. Moreover, an end surface 113 at the top end of the magnetic core part 105 may be worn or lost.
The vicinity of the gap part 110 of the magnetic core part 105 is ground so that its width is matched with that of a track part of a magnetic recording medium, and after that it is assembled to the magnetic head slider. Accordingly, this thinned part is liable to breakage during handling. Also since the coil 106 wound on the core part 105 is formed by winding of a lead wire, a special technology for handling a fine structure is required to assemble the coil 106 to the core part 105 whether it is assembled automatically or manually. Moreover, it takes a long time for such a subtle assembly.
In order to eliminate various disadvantages as described above, an object of the present invention is to provide a magnetic head slider to perform writing/reading of data with a magnetic recording medium in traveling, where the top end of the core part is not worn or lost and the data can be written and read stably even if the magnetic head slider contacts the magnetic recording medium of a hard type or flexible type. Another object of this invention is to provide a manufacturing method of a magnetic head slider that is simple and easy, according to which the core part of the magnetic head slider is not liable to breakage while it is assembled.